The life expectancy of people living in northern China is 5 ½ years less than in southern China as a result of the north’s notoriously bad air pollution, largely due to the burning of coal, according to a new study. In an analysis of air quality recordings from 90 Chinese cities from 1981 to 2000 and mortality data from the 1990s, a team of researchers estimated that high air pollution will cost the roughly 500

Getty Images

million people living north of the Huai River a combined 2.5 billion years of life expectancy compared with people living in the south. Writing in the Proceedings of the National Academy of Sciences, the researchers say increased mortality, attributable to cardiorespiratory illness, is the unintended consequence of a Chinese policy that from 1950 to 1980 provided free coal for boilers in cities north of the Huai, but not for those living in the south. According to the study, concentrations of total suspended particulates, or TSPs, exceeded 500 micrograms per cubic meter north of the Huai, about 55 percent higher than levels in the south. Earlier this year, some Chinese cities, including Beijing, recorded particulate-matter levels exceeding 700 micrograms per cubic meter. “Everyone understands it’s unpleasant to be in a polluted place,” said Michael Greenstone, a professor of environmental economics at MIT and one of the authors of the paper. “But to be able to say with some precision what the health costs are, and what the loss of life expectancy is, puts a finer point on the importance of finding policies that balance growth with environmental quality.”